From: Stefan Monnier <monnier@iro.umontreal.ca>
To: "Andreas Röhler" <andreas.roehler@online.de>
Cc: Dmitry Antipov <dmantipov@yandex.ru>, emacs-devel@gnu.org
Subject: Re: [RFC] bytecomp: simple source-level optimization
Date: Mon, 23 Jun 2014 10:19:44 -0400 [thread overview]
Message-ID: <jwvmwd3hfx9.fsf-monnier+emacs@gnu.org> (raw)
In-Reply-To: <53A7EEDE.2050506@online.de> ("Andreas Röhler"'s message of "Mon, 23 Jun 2014 11:09:50 +0200")
>> Source forms like:
>> (if (= (point) (point-min)) ...)
>> or:
>> (if (eq (point-max) (point)) ...)
>> are widely used,
> IMHO a very useful move. However, as this is suboptimal style,
> probably fixing the source --and spread the message-- is better than
> fixing it afterwards.
Indeed, it's very common for compilers to perform optimization of
"silly" expressions like (+ 4 5) or things like that. The purpose is
not to compensate for the stupidity of the programmer but to eliminate
stupidity introduced by earlier code transformations
(e.g. macro-expansion, inlinling or other optimizations).
If we thing it's undesirable source code, we should add warnings in the
byte-compiler. If OTOH we think it's perfectly fine source code (saving
the programmer the trouble of remembering the existence and meaning of
bobp/eobp), then it might be worthwhile to add the optimization in the
byte-compiler indeed.
Stefan
next prev parent reply other threads:[~2014-06-23 14:19 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-06-23 6:43 [RFC] bytecomp: simple source-level optimization Dmitry Antipov
2014-06-23 8:29 ` Leo Liu
2014-06-23 11:05 ` Dmitry Antipov
2014-06-23 12:26 ` Leo Liu
2014-06-23 9:09 ` Andreas Röhler
2014-06-23 12:44 ` Nicolas Richard
2014-06-23 14:01 ` Andreas Röhler
2014-06-23 14:19 ` Stefan Monnier [this message]
2014-06-23 9:56 ` David Kastrup
2014-06-23 11:40 ` Dmitry Antipov
2014-06-23 11:44 ` Dmitry Antipov
2014-06-25 1:08 ` Stephen J. Turnbull
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